Fourth-century sources make occasional complaints about tax rates. There was also one major tax riot. In Antioch in 387, a crowd gathered to protest about the imposition of a supertax. The mood got ugly, and imperial statues were toppled. Imperial images, like everything else to do with emperors, were sacred, and assaults on them an act of treason. The local community was terrified that army units might be turned loose on the city in punishment, but the reigning emperor, Theodosius I, took a conciliatory line to resolve the crisis. And this is a fair enough indicator of the general climate.
Tax collection goes more smoothly and rates can be increased more easily, if taxpayers understand and broadly accept the reasons for which they are being taxed. Fourth century emperors perfectly understood the principle of consent, and never lost an opportunity to stress that taxation paid above all for the army - which was true - and that the army was necessary to defend Roman society from outside threats. Most of the ceremonial occasions of the imperial year involved a keynote speech lasting about an hour whose purpose was to celebrate the regime's recent successes. Hardly any of our surviving late imperial examples fail to make some reference to the army and its function of protector of the Roman world.
Different emperors sold their frontier policies in different ways, but there was no disagreement on this basic purpose of taxation. The population was daily reminded of the point on its coinage: one of the most common designs featured an enemy grovelling at the emperor's feet. On the down side, military failings might be criticized for wasting the taxpayers' contributions.
In one famous incident, Ursulus, chief financial minister of the emperor Constantius II, complained sarcastically and publicly about the performance of the army on a visit to the ruins of Amida, shortly after the Persians sacked it in 359: 'Look at the courage with which the cities are defended by our soldiers, for whose huge salary bills the wealth of the Empire is already barely sutticient.' The generals didn't forget this. When Constantius died, part ot the price paid by his successor for their support was the condemnation to death of Ursulus in the political trials that marked the change of regime. For the most part, however, the system worked tolerably well; the Antioch tax riot is an isolated example, which was caused, notice, not by the usual taxes but by an additional imposition.
While, of course, many landowners sought to minimize their tax bills - the laws and letter collections are full of uncovered scams and requests for dispensations to this effect - fourth-century emperors did manage to sell to their population the idea that taxation was essential to civilized life, and generally collected the funds without ripping their society apart.Peter Heather, The Fall of the Roman Empire; pp. 120-121